1. Field of the Invention
The present invention relates to a method of and an apparatus for removing a film layer on a glass plate for removing a film layer formed on one surface of a glass plate which is used as laminated glass or the like for a window of an automobile or as double glazing or the like for a window of a general building, as well as a glass-plate working apparatus having that apparatus.
2. Description of the Related Art
Laminated glass having the function of shielding heat rays, ultraviolet rays, visible rays, or the like is formed such that film layers for shielding heat rays, ultraviolet rays, visible rays, or the like are respectively formed on one surfaces of two glass plates by sputtering (metallic deposition) and are inwardly opposed to each other, and pressure, heat, and the like are applied to the two glass plates with a polyvinyl butyral sheet placed therebetween, thereby bonding the film layers and the polyvinyl butyral sheet. However, since the film layers and the polyvinyl butyral sheet are difficult to bond to each other, the state of their bonding is likely to become incomplete, and moisture, air, and the like can possibly enter peripheral portions of the laminated glass where the state of bonding is incomplete. Consequently, the polyvinyl butyral sheet becomes oxidized and undergoes color development and change. Accordingly, there is a need to remove the film layers at the peripheral portions so as to bond the glass plates and the polyvinyl butyral sheet which are easily bonded to each other. Meanwhile, double glazing having the function of shielding heat rays, ultraviolet rays, visible rays, or the like is formed such that film layers are respectively formed on one surfaces of two glass plates and are inwardly opposed to each other, and in order to obtain a hermetically sealed state between them, spacers are inserted between and bonded to the two glass plates at their peripheral portions by means of a pressure-sensitive adhesive elastic material (hereafter referred to as butyl rubber) formed of butyl and Thiokol (trade name). However, since the film layers and the butyl rubber are difficult to bond to each other, the state of their bonding is likely to become incomplete, and moisture and the like can possibly enter those portions where the state of bonding is incomplete, making it impossible to maintain the hermetically sealed state. Consequently, the heat insulating effect deteriorates appreciably, and water droplets and the like can occur on the film layers. Therefore, there is a need to remove the film layers at the peripheral portions so as to bond the glass plates and the butyl rubber which are easily bonded to each other.
In conjunction with the trend of automation of the motor vehicle traffic system in recent years, for example, automatic collection of a toll and the like is planned to be implemented in which an information recording medium such as a card is set on the windshield glass side in a vehicle, and the relevant information is automatically read from outside the vehicle by light rays for reading the information recorded on the card or the like. However, in the case where the film layers for shielding heat rays, ultraviolet rays, or the like are formed in the windshield glass of the vehicle, the transmittance of the reading light rays declines when the light rays are transmitted through the film layers, so that it is difficult to always reliably read the information recorded on the card or the like. Further, a stop lamp is provided on the rear window glass side inside a vehicle so as to rouse the attention of a following vehicle when a vehicle during traveling undergoes deceleration, stopping, or the like. However, in the case where the film layers (particularly dark-colored film layers) are formed in the rear window glass, when the light rays emitted from the stop lamp are transmitted through the film layers, the transmittance of the light rays declines. Hence, it is impossible to rouse sufficient attention of the following vehicle, and there is a risk of leading to a traffic accident such as a collision from behind. Accordingly, there is a need to enhance the transmittance of such light rays by removing (cutting off) the film layers in regions where the reading light rays and the light rays of the stop lamp are transmitted.
For the above reasons, regions and portions for which the film layers in the glass plates need to be removed are tending to increase.
Incidentally, in the case of removing a film layer for shielding heat rays, ultraviolet rays, visible rays, or the like, which is formed on one surface of a glass plate used for a vehicle, a general building, or the like for the purpose of maintenance of health, improvement of comfort, securing of privacy, and the like, the film layer in a specific region of the glass plate is conventionally removed while numerically controlling the movement of one removing head.
However, since the regions and portions for which the film layers in the glass plates need to be removed are tending to increase, as described above, a long time is required for removing the film layers in predetermined regions of the glass plates in a case where the single removing head is used. Hence, the improvement of productivity of these glass plates has been difficult, and has been a problem particularly in the working of window glass for motor vehicles for which high productivity is required.
The present invention has been devised in view of the above-described aspects, and its object is to provide a method of and an apparatus for removing a film layer in a specific region of a glass plate in a short time, and a glass-plate working apparatus having that apparatus.
To this end, in accordance with a first aspect of the invention, there is provided a method of removing a film layer on a glass plate, comprising the steps of: defining in a divided manner a region of a film layer to be removed on a glass plate; and concurrently effecting removal of the film layer on the glass plate in an apportioned manner with respect to respective divided regions defined in the divided manner.
In the method of removing a film layer on a glass plate in accordance with the invention, the region of the film layer to be removed on the glass plate is preferably defined in a divided manner in accordance with at least any one of conditions including its area, shape, and removal time.
According to the method of removing a film layer on a glass plate in accordance with the invention, since the region of the film layer to be removed on the glass plate is defined in a divided manner, preferably defined in a divided manner in accordance with at least any one of conditions including its area, shape, and removal time, and the removal of the film layer on the glass plate is concurrently effected in an apportioned manner with respect to divided regions defined in the divided manner, the film layer in a specific region of the glass plate can be removed in a short time.
In the method of removing a film layer on a glass plate in accordance with the invention, the region of the film layer to be removed on the glass plate may preferably be defined in the divided manner such that areas of the respective divided regions assume mutually substantially identical areas, or such that durations of removal time for removing the film layer in the respective divided regions are set to mutually substantially identical durations. Since the region of the film layer to be removed on the glass plate is defined in the divided manner such that areas of the respective divided regions assume mutually substantially identical areas, or such that durations of removal time for removing the film layer in the respective divided regions are set to mutually substantially identical durations, the respective operations of removing the film layer in the regions to be removed on the glass plate can be effected in a mutually complementary manner. Thus, the film layer in a specific region of the glass plate can be removed in a short time.
In the method of removing a film layer on a glass plate in accordance with the invention, a position at which the removal of the film layer is started in each of the divided regions is preferably determined in accordance with the shape of each of the divided regions.
In accordance with a second aspect of the invention, there is provided an apparatus for removing a film layer on a glass plate, comprising: at least first and second removing means for removing a film layer on a glass plate, wherein a region of a film layer to be removed on a glass plate is defined in a divided manner, and with respect to divided regions defined in the divided manner the removal of the film layer on the glass plate is effected concurrently by being apportioned to the first and second removing means.
In the apparatus for removing a film layer on a glass plate in accordance with the invention, the region of the film layer to be removed on the glass plate is preferably defined in the divided manner in accordance with at least any one of conditions including its area, shape, and removal time.
According to the apparatus for removing a film layer on a glass plate in accordance with the invention, since the region of the film layer to be removed on the glass plate is defined in a divided manner, preferably defined in a divided manner in accordance with at least any one of conditions including its area, shape, and removal time, and the removal of the film layer on the glass plate is apportioned to the first and second removing means and is concurrently effected by these means in an apportioned manner with respect to divided regions defined in the divided manner, the film layer in a specific region of the glass plate can be removed in a short time.
In the apparatus for removing a film layer on a glass plate in accordance with the invention, the region of the film layer to be removed on the glass plate may preferably be defined in the divided manner such that areas of the respective divided regions assume mutually substantially identical areas, or the region of the film layer to be removed on the glass plate may be defined in the divided manner such that durations of removal time for removing the film layer in the respective divided regions are set to mutually substantially identical durations. Since the region of the film layer to be removed on the glass plate is defined in the divided manner such that areas of the respective divided regions assume mutually substantially identical areas, or such that durations of removal time for removing the film layer in the respective divided regions are set to mutually substantially identical durations, the respective operations of removing the film layer in the regions to be removed on the glass plate by the first and second removing means can be effected in a mutually complementary manner. Thus, the film layer in a specific region of the glass plate can be removed in a short time.
In the apparatus for removing a film layer on a glass plate in accordance with the invention, a position at which the removal of the film layer is started in each of the divided regions by the first and second removal means is determined in accordance with the shape of each of the divided regions. Since the position at which the removal of the film layer is started in each of the divided regions by the first and second removal means is determined in accordance with the shape of each of the divided regions, the first and second removing means are able to remove the film layer on the glass plate smoothly without interfering with or colliding against each other.
The apparatus for removing a film layer on a glass plate in accordance with the invention preferably further comprises: transporting means for transporting the glass plate, wherein the first and second removing means respectively have grinding wheels for grinding and removing the film layer on the glass plate, the grinding wheels being arranged on both sides of a path for transporting the glass plate by the transporting means.
In accordance with a third aspect of the invention, there is provided a glass-plate working apparatus comprising: the apparatus for removing a film layer on a glass plate according to the second aspect of the invention; bend-breaking means for bend-breaking a glass plate whose film layer has been removed; grinding means for grinding peripheries of the glass plate bend-broken by the bend-breaking means; and transporting means for transporting the glass plate consecutively to the apparatus for removing a film layer, the bend-breaking means, and the grinding means. Further, in this glass-plate working apparatus as well, the first and second removing means may preferably be respectively comprised of grinding wheels for grinding and removing the film layer on the glass plate, the grinding wheels being arranged on both sides of a path for transporting the glass plate by the transporting means.
According to the glass-plate working apparatus in accordance with the invention, the removal of the film layer by the apparatus for removing a film layer on a glass plate, the bend-breaking by the bend-breaking means of the glass plate whose film layer has been removed, and the grinding of the peripheries of the bend-broken glass plate by the grinding means can be effected concurrently. In addition, the removal of the film layer, bend-breaking, and grinding can be effected in an integrated manner in a production line by a single apparatus.
The bend-breaking means of the glass-plate working apparatus in accordance with the invention preferably includes cutting means for forming a cut line for bend-breaking the glass plate whose film layer has been removed and press-breaking means for press-breaking along the cut line the glass plate on which the cut line has been formed.
The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of the invention when read in conjunction with the accompanying drawings.